Police said the 25-year-old victim agreed to meet Estrada in the parking lot at the Carmans Plaza Shopping Center in Massapequa. When she got into his car, Estrada attacked, punching her and stabbing her 13 times with a knife, police said.

Good Samaritans rushed to help after hearing screaming from their SUV, Mike Spiachalsky, an ambulette driver who stopped there for breakfast, told NBC 4 New York.

In an effort to help, Spiachalsky said they smashed one of the SUV's windows and opened the door. The woman came out bloody with multiple stab wounds, he said.

As bystanders like Romann Martin of Amityville tended to her, Estrada, still inside the SUV, stabbed himself four times in the chest, police and witnesses said.

The victim was airlifted to an area hospital, where she is in stable but critical condition. Estrada was taken by ambulance to an area hospital, and is also listed in stable but critical condition.

Estrada is scheduled to be arraigned in the hospital at a later date. No information on an attorney was available.